If you're coming from the TV show 'Shadowhunters' or the movie 'City of Bones', the book order is still the same. Those adaptations took liberties and condensed plots, so don't assume you know what will happen. Start from book one, 'City of Bones'. The book introduces characters and relationships differently, and the lore is much more detailed.
The show, in particular, incorporated elements from later books and other series very early on. So reading in the standard 1-6 order will still feel fresh, even if you know some major plot points. You'll get the fuller, richer version of the story as it was originally written. Consider the adaptations as separate, alternate-universe versions.